We were also surprised by the slow restore from B2 buckets; it turns out that B2 download speed is limited to ~35 Mbps so still much more than what you were getting. It is still very slow when you have a 300 Mbps fiber connection but have to wait 16 hours to restore a small workstation. We do both local and cloud backups for this very reason.

I'm not using synthetic full as its not supported with my B2 storage yet (unless that changed). I'm doing image backup full weekly and incremental daily; so for a small office I spread full over different days; so machine 1 does full on Monday, machine 2 on Tuesday .. I also run jobs to storage locally onsite still typically shared USB drives or NAS drives; that goes a lot faster and staggering them tighter is possible. So I'd like the remote deploy config of schedules to have options for spreading the backups. My old Acronis backup through my Kaseya could easily be commanded to do this.

it would be very nice if the backup plans would then be staggered so not all machines run backup at 8 pm simultaneously. it appears there is no such function in the settings for schedule?!

I have ~100 machines split in ~10 networks doing incremental image to a shared LAN storage nightly, with full image backup weekly, keeping as much as we can hold. There seem to be no way the backup agents can 'taste' how much space is left on the storage location. We also do some cloud file and image backups though less frequent and use B2 as storage. Its important that your B2 buckets are set to keep just a single version - as per CBB support.

I'm seeing this a lot too these days ... on machines where CBB is the only backup operation on those systems. the backups are scheduled after work hours. Some machines run Win7 some run Win10.. just today was 6 machines throwing this error... so in CBB MBS I'll manually run the job and it will run/finish successfully.. This problem has been going on for a couple of months only.